Simulation Theory is packed with high-frequency synthesizer sweeps, layered arpeggios (e.g., "Algorithm," "Blockades"), and sub-bass drops. MP3 compression (320kbps or lower) cuts frequencies above 16-18kHz and uses bitrate reduction that smears transients. FLAC preserves the (or higher if ripped from a 24-bit source). On a good PC sound card or external DAC, the difference is night and day.